Sarah Ingham is a PhD candidate at the War Studies Department at King’s College London.

Tomorrow's Armed Forces Day will see the RAF’s Red Arrows fly over Edinburgh: the scream of jet engines should just about be able to drown out Britain’s collective tut-tutting over the Greeks’ catastrophic mismanagement of their economy.

If the Spitfires, Hurricanes and Lancasters of the Battle of Britain Memorial Flight put in an appearance, thoughts might well turn to Germany, rescuer-in-chief of those spendthrift Hellenes, with their bloated public sector and addiction to foreign taxpayers’ largesse.

Half a century ago, Prime Minister Macmillan suggested to President Kennedy that Britain was Greece to America’s Rome. Today, when it comes to defence, Britain is Greece to America’s Germany.

The NATO action in Libya could see a shift in the strategic and defence landscape – Suez redux for the early 21st Century. Back in 1956, the United States gave Britain and France a pretty brutal lesson about the new realities of global power. Fast-forward to today and we are being taught that military intervention comes at a price. And, if the Americans aren’t prepared to pick up at least some of the tab, it’s a price that Britain can no longer afford.

A few weeks ago the out-going US Defense Secretary Robert Gates warned NATO members about the ‘dwindling appetite’ of Congress and, perhaps more importantly of American taxpayers, for their increasingly precious dollars to be spent on subsidising their NATO allies – especially those allies who have chronically starved their defence budgets. Although Britain was acknowledged to be a ‘military stalwart’ and is one of the handful of Alliance members which fulfils the agreed commitment to spend at least 2% of GDP on defence, it was noted that we have had to ‘ratchet back with major cuts to force structure’. Which is one way of describing the recent scrapping of Harriers, Nimrods, a chunk of the Naval Fleet including the Ark Royal, an order for Chinooks and 17,000 Armed Forces personnel.

Apart from a brief spell in the 1990s, American defence spending is at its lowest point since the Second World War – standing at 3.5% of GDP. Even so, it is colossal. So much so that in July 2009 at the start of Operation Khanjar, 4,000 US Marines could be flown into Helmand in, reportedly, almost 90 helicopters. As Stalin once said of his tanks, quantity has a quality all of its own.

Although the operation against Libya is under NATO auspices, after an initial volley of Tomahawk cruise missiles back in March, the US is remaining fairly aloof from the action. Like Suez, Libya is an Anglo-French initiative. To paraphrase former Secretary of State James Baker, the United States never wanted to have a dog in the fight. Especially if the fight is in what is effectively Europe’s back yard.

Meanwhile back in Britain, where the RAF is ‘running hot’ according to its second-in-command Air Chief Marshal Sir Simon Bryant, the First Sea Lord Sir Mark Stanhope has warned the country’s defences could soon be ‘at risk’ if the Operation Ellamy should continue beyond six months. Both men are concerned about the morale of Armed Forces’ personnel, reflected by the news that twice than the expected number of Army officers have applied for voluntary redundancy.

Libya, like Suez, could be a turning point. Just as those industrious Germans no longer want to shell out so that Greeks can enjoy early retirement, hard-working Americans no longer want to bankroll the NHS – or British pretensions to being a military super-power. And who can blame them?

If the US is ripping away its defence and security blanket from NATO, the UK is going to have to huddle militarily closer to its European neighbour.

Like Greece, Britain has an illustrious history. The Armed Forces have played a central role in that history and are a key part of Britain’s national identity. They are rightly being celebrated tomorrow.

Unlike Greece, we are still a rich nation, holding on to a certain degree of financial autonomy. We can still decide where our taxes should be spent. Armed Forces Day is perhaps also a chance for us to reflect as well as celebrate. Is Britain’s place in the world dependent on military power? Do we still want permanent membership of the UN Security Council? Is it our duty to intervene in Libya? Or Syria? Conversely, perhaps our Armed Forces offer such a comparative advantage, they are more of a worthwhile investment for UK plc than almost any other branch of the public sector?

Britain has to decide whether we want welfare or warfare. We can’t afford both. And neither can the United States.